import java.util.Scanner;
public class Main {

	public static void main(String[] args) {
		int[] arr=new int [1];
		String str=null;
		Scanner in=new Scanner(System.in);
		while(true)
		{
			String choice=in.next();
			try{
				
				if(choice.equals("arr")){
					int index=in.nextInt();
					arr[index]=1;
				}
				else if(choice.equals("null")){
					str.length();
				}
				else if(choice.equals("cast")){
				Object x=new String("a");
				System.out.println((Integer)x);
				
				}
				else if(choice.equals("num")){
					String intNum=in.next();
					Integer.parseInt(intNum);
				}
				else{
					break;
				}
			}catch(Exception e){
				System.out.println(e);
			}
		}
			
			in.close();
	}

}